Kournikova's hiring is part of an effort to revamp the reality show. "The Biggest Loser" Executive Producer Todd Lubin tells Vulture that next season viewers will see the show "getting slightly away from just the tape measure, and getting into overall well being and health."

She made an appearance on the show in October 2010 where she led a tennis work-out challenge.

Her debut appearance was brought down by the fact that her team finished in last place for the night. The team, which is labeled as the blue team, only lost 43 pounds total for the week. Veteran "Biggest Loser" trainer Bob Harper's team (the black team) won the night, losing 126 pounds total. Fellow trainer Dolvett Quince's red team lost 89 pounds.

The athlete is also known for her relationship with pop star Enrique Iglesias that began in 2001. During an interview with Graham Norton on BBC in 2010, she confirmed that the two are still dating but have no interest in getting married.

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